This study focuses on the evaluation of a traditional treatment, viz., thiamine or vitamin B2, administered to a nontraditional population, i.e., alcoholic patients without Wernicke-Korsakoff's Syndrome. The principal aim of the study is to examine the potentially beneficial effects of a 5 gram oral dose of thiamine versus a matching placebo on the cognitive status of alcohol-dependent patients (n=20) and normal non-drug-dependent volunteers (n=15). Thiamine or placebo is administered (in counterbalanced order)on consecutive days. It is hypothesized that the patients with histories of alcohol dependence will benefit more from thiamine therapy. The study is ongoing with additional data collection expected.